Palladium nickel alloy



Patented Mar. 23,. 1937 UNITED STATES YPATENT OFFICE PALLADIUM NICKELALLQY Sidney 001m,- New rm, N. Y., assignor m v Sigmund (John, New York,N. Y.

No Drawing. Application December 22, 1986, Serial No. 117,150

4 Claims. (01. 75-112) by alloying it with costly or rare metals suchas:

ruthenium, rhodium, platinum, etc.

In accordance with my present invention, I provide a commercially hardpalladium alloy by the addition of the base metal nickel to palladium.Nickel is comparatively very cheap and has substantially the same coloras palladium. -I have 30 found that by proper proportioning of thenickel content, a hard palladium alloy-is produced, having the whiteappearance of palladium, and being resistant to oxidation anddiscoloration. 1 The relatively high fusion point of thepalladium-nickel alloy of my invention, together with the whiteappearance and workability of the metal, renders it widely useful. Theelasticity and springiness of the alloy make it suitable for opticalframes and other uses. It is accordingly an object of my presentinvention to provide a novel alloy of palladium.

Another object of my present invention is to provide a novel palladiumalloy of commercial hardness. 5 A further object of my present inventionis to provide a novel palladium alloy hardened by the base metal nickel.

A still further object of my present invention is to provide a novelpalladium nickel alloy go having the appearance of palladium and beingresistant to oxidation and tarnishing.-

Other objects and advantages of my present invention will be evidentfrom the following description.

5 I have discovered that by alloying palladium with four to sixper centof nickel produces the qualities in palladium hereinabove described. Inpractice, I have found that as the percentage of nickel content isincreased up tosixteen per cent, 5othehardnessrisesrapidly. 1

- At sixteen per cent nickel. the alloy' has a tendency to crack and canbe wofked satisfactorily only when hot. Beyond this percentage ofnickel, the alloy begins to present considerable 55 Sixteen per centnickel may therefore be considered the upper limit of thepalladium-nickel composition of this invention. Nickel, having a colorsimilar to palladium, does not affect the color of the palladium alloyin the proportions used. The alloy is cold-rolled to suitable shape in amanner well known in the art and is annealed by heating to a temperatureof 800 to 1000" C. and permitted to cool slowly under atmosphericconditions. -In order to prevent the formation of oxide coatings on thepalladium alloy, I water quench the alloy.

I have found that the addition of a small quan tity of flux when thealloy is first prepared from its elementary constituents, prevents theformation of nickel oxide. This is important, inasmuch as nickel oxideinclinm the alloy to be brittle.

After the nickel has been melted in the palladium,

the standard technique as used in melting pure palladium can be followedingof the alloy. I

Rockwell'hardness measurements on pure palladium using the B scale rangefrom -40 to -50.

Similar hardness measurements on the palladiumfour per cent nickel alloyof my present invention showed +30 to measurements on'the palladium-fiveper cent nickel composition yielding +53 to +55; six per cent yieldinfor subsequent melt- The resultant palladium-nickel alloy has the lwhite appearance of-palladiumand suitable commercial hardness forjewelry, watch-cases, rings and the like, serving as a good andeconomical substitute for. white gold and/or platinum. This alloy isresistant .to oxidation, acids, and dis-' malleability and workabilityof the alloy renders it, as stated, suitable for a wide variety of usesand produces a springiness' or elasticity and malleability making ituseful for jewelry generally.

' I claim: I

P 1. An alloyconsisting of approximately ninetyfive percent palladiumand approximatelyv five percent nickel.

2.- An alloy constituted principally of pailadium, ninety-seven toninety two percent having a corresponding nickel content of three toeight percent.

3. Analloycomposed of and nickel having from five to sixteen percentnickel content. 4. An alloy constitutedprlncipally of palladium ofapproximately ninety-five percent, hardened with nickel to aRockwell-hardness of the-order'of

